Water Use, Overuse, and Natural Contamination

Withdrawals exceed recharge creating deficits in the aquiferOver-exploitation of renewableand non-renewable aquifers

Water MiningLack of contemporary recharge

ChinaIndiaIranIsraelJordanMexicoMoroccoPakistanSaudi Arabia South Korea SpainSyriaTunisiaUnited States Yemen

Saudi Arabia and Libya, use 77% of the estimated total world extraction of non-renewable groundwater for urban supply and irrigated agriculture.The Middle East

GROUNDWATER . (Mm3/yr) COUNTRY Total use % Non-renewableSaudi Arabia 21,00084%Bahrain 25835%Egypt 4,85018%Jordan 48635%Libya 4,28070%Yemen 2,20032%

Falls in the water table between 1982 and 2000 range from 3 to 6 feet per yearWithin 15 years Quetta will run out of water if the current consumption rate continuesPakistan

Water table falling by 8.5 feet per yearIran: Water Refugeesover pumping by an average of 5 billion tons (3.7 Ma-f)of water per yearEquivalent to 1/3 Irans annual grain harvestMashadVillages Abandoned

71 percent drop in wheat harvest from a high of 4.1 million tons in 1992 to 1.2 million tons in 2005, Saudi farmers are now pumping water from wellsthat are 4,000 feet deepPaleowater35,000 years oldQa-Disi Aquifer

water extraction exceeds the annual recharge by a factor of five, Yemenpumped dry by 2010Options:

relocate the capitalpipelinesWater table dropping 6 meters (18 ft) per year

Other Large Deficits

Deep wells must reach more than half a mile to tap fresh waterLevel of the deep aquifer is dropping nearly 3 meters (10 feet) per year Deficit feeds 100 million peopleShallow , unconfinedaquifer depleted

water table falling by 20 feet per yearDeficit feeds 200 million21 million wellsFailure of 246 surface irrigation projects$600 electric pumps (1% of GDP)Deficit of 80 million acre-feetIndia95 %

5 acres of landPumps 3200 gallons/hr

Irrigates alfalfa for 64 hours

24 times per yearYield: 6.5 gallons milk/day4.9 million gallons => 2400 gallons milk (2000 gallons water/ gallon milk)4.9 million gallons water/yr

United States

United States1/3 of irrigation water comes from groundwaterThe 3 largest aquifers are in arid/semi-arid regionsOgallala AquiferMidwestCentral Valley AquiferCaliforniaSouthwest Aquifer SystemArizona, Utah, Nevada

Central Valley Aquifer (California)Pumping 15% more water than is replacedSouthwest Aquifer (Utah, Nevada, Arizona)Pumping 50% more water than is replacedDeficit of 30 million acre-feetWater storage capacity has declined by 50%High Plains Aquifer (Ogallala) gone in areas of Texas, Oklahoma, KansasWater table declines up to 100 feet in some areas

Phoenix ArizonaGrowing 2 acres/hrAmong the highest water users

tripled in population over the last 40 years Tucson

Canal 335 miles long44 billion gallons/yr7% lost to evaporationCentral Arizona Project

Use, Overuse, Quality

USTsLandfillsSeptic systemsUrban RunoffAgricultureIndustryRainfall

ContaminantSources

Natural Groundwater Contaminants

Tapping water as deep as 1,000 meterswater table falling by 20 feet per year21 million wellsIndia

Deeper Wells and Fluoride Naturally occurring element in Granitewhich dissolves into the groundwaterWater near the surface is generally unaffectedLowering water tables = deeper wellsDeep groundwater contains high fluoride levelsfluoride in water can be a cumulative poison

Intentional Fluoridation of Water in the U.S.Fluoridation became an official policy of the U.S. Public Health Service in 1951.

By 1960 water fluoridation had become widely used in the U.S. reaching about 50million people.

By 2006, 69.2% of the U.S. population on public water systems were receiving fluoridated water.

How does it work?Tooth enamel is made of a mineral called hydroxyapatiteCa5(PO4)3OHHydroxyapatite is subject to dissolution by acids (H+)Fluoridation changes the chemical composition ofhydroxyapatite to a crystal less subject to acid dissolutionBacteria in the mouth create acids (H+)

Ca5(PO4)3Sodium fluorosilicate (Na2SiF6) Sodium fluoride (NaF) OHIngestion of fluoridated water increases the F- concentration in salivaF- replaces OH in hydroxyapatite making fluoroapatiteF-Fluoroapatite is less soluble in acid than hydroxyapatite

Fluoride concentrationsIn U.S. tap water0.6 1.1 mg/LLower values in warm climates

1.6 to 6.6 mg/day Colorado Brown StainDental FluorosisIntake:Permissible fluoride limit in India is 1.2 mg/LFluoride levels between 5-25 mg/L have been foundFluoride levels > 1.5 mg/L

9 mg/day to 12 mg/day Fluorosis has risen from 1 million to 25 million and now to 60 million people in India.Skeletal FluorosisIntake Fluoride levels > 10 mg/L

Groundwater and Arsenic

Arsenic is Naturally Occurring occurs primarily in association with sulfur-containing mineralsmean values of arsenic content in soils, the earths crust, and sediments are between 1.5, and 7.7 mg/kgMobilization of arsenic in the environment arises from anthropogenic activities related to mining and ore processing, metallurgy, agriculture, wood preservation, and industry.Natural waters, in general, contain low levels of total arsenic

Inorganic Forms of Arsenic AsO4-3AsO3-3ArseniteArsenateLow OxygenHigh OxygenArsenite is more toxic than arsenate, interfering withenzyme activities which catalyze metabolic reactionsArsenite compounds are also more mobile in the environmentdue to higher solubility compared to arsenate compoundsBoth arsenate and arsenite are chronic accumulative toxins

The Worlds Largest Mass Poisoning

Bangladesh and W. Indiaranked among the world's 10 poorest countries

Accumulation ofthick mudsin the floodplainsand deltasFloodplain and Delta of theGanges and Brahmaputra Rivers.Floodplain: area paralleling a river that is periodically inundatedDeltas are formed from the deposition of sediment carried by the river as the flow leaves the mouth of the riverHimalayasGanges-Brahmaputra Delta

Prior to 1970sOne of the highest infant mortality rates in the worldPrincipally due to waterborne disease.Ineffective water and sewage systemsPeriodic monsoons and floodscholera, dysenterywater-borne pathogensDeaths Due to Surface water contamination: 250,000/yr

Deaths Due to Surface water contamination: 250,000/yrThe Solution: Tap groundwater resources

easy inexpensiveFirst 1 million were sunk with aid fromWorld GovernmentsUNICEFWorld Bank

Infant mortality and diarrheal illness reduced by 50%

Wells in Floodplain and Delta Sediments Water Bearing MudsNatural erosion ofarsenic to water-bearing units.Well depths between 20m and 100 m

Majority of wells > 50 ppb arsenicSome wells contain 500 - 1000 ppbWHO/U.S limit: 10 ppbBangladesh limit: 50 ppb

Exposure EstimatesAbove 50 ppb:35 million

Above 10 ppb:57 millionEarly Symptoms:

Skin lesions and thickeningStrong skin pigmentation

2003 Studies

83 million peopleBihar: 40% wells contaminated

Red River Delta11 million people

First wells sunk7 years ago

End Lecture 17

Next: Floridas Aquifers

Sea LevelsTemporary reestablishment of carbonate deposition

VulnerabilityOne gallon of gasoline cancontaminate 1 million gallonsof drinking water1 ppm

MetalsNutrientsPesticidesPetroleum Solvents

*For fossil aquifers, such as the vast U.S. Ogallala aquifer, the deep aquifer under the North China Plain, or the Saudi aquifer, depletion brings pumping to an end. Farmers who lose their irrigation water have the option of returning to lower-yield dryland farming if rainfall permits. In more arid regions, however, such as in the southwestern United States or the Middle East, the loss of irrigation water means the end of agriculture. *On the basis of available statistics (undoubtedly incomplete) the global mining of groundwater is currently put at some 27,000 Mm3/a, and if this figure is compared to the current total rate of groundwater exploitation, provisionally put at 670,000 Mm3/a (Shiklomanov, 1998), the proportion derived from groundwater mining is 4%. This production is mainly concentrated in Saudi Arabia and Libya, who have some 77% of the estimated total world extraction of non-renewable groundwater. In both these cases non-renewable groundwater represents an important or predominant source of water-supply (84% in Saudi Arabia and 67% in Libya), and is used for urban water-supply and for irrigated agriculture. Certain other huge aquifers, such as the North China*Pakistan, a country with 158 million people that is growing by 3 million per year, is also mining its underground water. In the Pakistani part of the fertile Punjab plain, the drop in water tables appears to be similar to that in India. Observation wells near the twin cities of Islamabad and Rawalpindi show a fall in the water table between 1982 and 2000 that ranges from 1 to nearly 2 meters a year. 20In the province of Baluchistan, water tables around the capital, Quetta, are falling by 3.5 meters per year. Richard Garstang, a water expert with the World Wildlife Fund and a participant in a study of Pakistans water situation, said in 2001 that within 15 years Quetta will run out of water if the current consumption rate continues. 21The water shortage in Baluchistan is province-wide. Sardar Riaz A. Khan, former director of Pakistans Arid Zone Research Institute in Quetta, reports that six basins have exhausted their groundwater supplies, leaving their irrigated lands barren. Khan expects that within 1015 years virtually all the basins outside the canal-irrigated areas will have depleted their groundwater supplies, depriving the province of much of its grain harvest. 22*Iran, a country of 70 million people, is overpumping its aquifers by an average of 5 billion tons of water per year, the water equivalent of one third of its annual grain harvest. Under the small but agriculturally rich Chenaran Plain in northeastern Iran, the water table was falling by 2.8 meters a year in the late 1990s. New wells being drilled both for irrigation and to supply the nearby city of Mashad are responsible. Villages in eastern Iran are being abandoned as wells go dry, generating a flow of water refugees. *Saudi Arabia, a country of 25 million people, is as water-poor as it is oil-rich. Relying heavily on subsidies, it developed an extensive irrigated agriculture based largely on its deep fossil aquifer. After several years of using oil money to support wheat prices at five times the world market level, the government was forced to face fiscal reality and cut the subsidies. Its wheat harvest dropped from a high of 4.1 million tons in 1992 to 1.2 million tons in 2005, a drop of 71 percent. 25Craig Smith writes in the New York Times, From the air, the circular wheat fields of this arid lands breadbasket look like forest green poker chips strewn across the brown desert. But they are outnumbered by the ghostly silhouettes of fields left to fade back into the sand, places where the kingdoms gamble on agriculture has sucked precious aquifers dry. Some Saudi farmers are now pumping water from wells that are 4,000 feet deep, nearly four fifths of a mile (1 mile equals 1.61 kilometers). 26A 1984 Saudi national survey reported fossil water reserves at 462 billion tons. Half of that, Smith reports, has probably disappeared by now. This suggests that irrigated agriculture could last for another decade or so and then will largely vanish, limited to the small area that can be irrigated with water from the shallow aquifers that are replenished by the kingdoms sparse rainfall. It is a classic example of an overshoot-and-collapse food economy.*In neighboring Yemen, a nation of 21 million, the water table under most of the country is falling by roughly 2 meters a year as water use outstrips the sustainable yield of aquifers. In western Yemens Sanaa Basin, the estimated annual water extraction of 224 million tons exceeds the annual recharge of 42 million tons by a factor of five, dropping the water table 6 meters per year. World Bank projections indicate the Sanaa Basinsite of the national capital, Sanaa, and home to 2 million peoplewill be pumped dry by 2010. 28In the search for water, the Yemeni government has drilled test wells in the basin that are 2 kilometers (1.2 miles) deepdepths normally associated with the oil industrybut they have failed to find water. Yemen must soon decide whether to bring water to Sanaa, possibly by pipeline from coastal desalting plants, if it can afford it, or to relocate the capital. Either alternative will be costly and potentially traumatic. 29With its population growing at 3 percent a year and with water tables falling everywhere, Yemen is fast becoming a hydrological basket case. Aside from the effect of overpumping on the capital, World Bank official Christopher Ward observes that groundwater is being mined at such a rate that parts of the rural economy could disappear within a generation. 30*In terms of available freshwater: groundwater, Lakes, soils, wetlands and rivers yield 0.775% of total.*concerns are mirrored in a World Bank report: Anecdotal evidence suggests that deep wells [drilled] around Beijing now have to reach 1,000 meters [more than half a mile] to tap fresh water, adding dramatically to the cost of supply. In unusually strong language for a Bank report, it foresees catastrophic consequences for future generations unless water use and supply can quickly be brought back into balance *In Tamil Nadu, a state with more than 62 million people in southern India, wells are going dry almost everywhere. According to Kuppannan Palanisami of Tamil Nadu Agricultural University, falling water tables have dried up 95 percent of the wells owned by small farmers, reducing the irrigated area in the state by half over the last decade. 16As water tables fall, well drillers are using modified oil-drilling technology to reach water, going as deep as 1,000 meters in some locations. In communities where underground water sources have dried up entirely, all agriculture is rain-fed and drinking water is trucked in. Tushaar Shah, who heads the International Water Management Institutes groundwater station in Gujarat, says of Indias water situation, When the balloon bursts, untold anarchy will be the lot of rural India. 17At this point, the harvests of wheat and rice, Indias principal food grains, are still increasing. But within the next few years, the loss of irrigation water could override technological progress and start shrinking the harvest in some areas, as it is already doing in China. 18*The Central Valley is one of the most important agricultural areas in the world. No single region of comparable size in the United States produces more fruits, vegetables, and nuts. More than 7 million acres are currently (1995) under irrigation. During 1985, crop irrigation accounted for 96 percent of the surface water and 89 percent of the ground water withdrawn in the Central Valley. *Middle of the Sonoran Desert*Tucsons portion of Colorado River water, about 44 billion gallons each year, comes to us through the Central ArizonaProject canal, a 335-mile long channel that begins near Lake Havasu, passes through the Phoenix area and rural PinalCounty, and ends about 15 miles south of Tucson*In Tamil Nadu, a state with more than 62 million people in southern India, wells are going dry almost everywhere. According to Kuppannan Palanisami of Tamil Nadu Agricultural University, falling water tables have dried up 95 percent of the wells owned by small farmers, reducing the irrigated area in the state by half over the last decade. 16As water tables fall, well drillers are using modified oil-drilling technology to reach water, going as deep as 1,000 meters in some locations. In communities where underground water sources have dried up entirely, all agriculture is rain-fed and drinking water is trucked in. Tushaar Shah, who heads the International Water Management Institutes groundwater station in Gujarat, says of Indias water situation, When the balloon bursts, untold anarchy will be the lot of rural India. 17At this point, the harvests of wheat and rice, Indias principal food grains, are still increasing. But within the next few years, the loss of irrigation water could override technological progress and start shrinking the harvest in some areas, as it is already doing in China. 18mining and ore processing, metallurgy,agriculture, wood preservation, and industry.*Old U.S. standard was 50 ppb, but was changed to 10 ppb in 2006. This put between 35 and 38% of wells out of compliance in Arizona and California.*